Kidneys are the most executable pair of organs of the body. The kidneys purify the blood of unnecessary substances which are then discharged through the urethra. Kidney disease is one of the costliest illnesses in the world and managing kidney disease is very expensive. Kidney failure is often due to the build-up of waste products in the body. Inability to remove potassium from the bloodstream may lead to abnormal heart rhythms and sudden death.

Pain-killer abuse
Too much use of pain-killers for simple pain is a bad habit. Most pain-killers have severe side effects and can damage different organs, such as kidneys. Studies show taking pain killers long term reduces blood flow and deteriorates the kidney's main function.

Alcohol consumption
Too much alcohol consumption damages our kidney and liver. Drinking on limit is not bad but most of us don't stop after just one drink. Alcohol is actually a legal toxin that puts a lot of stress on our kidneys and liver.

Not drinking water
Proper hydration is needed for the kidneys to function well. If we don't drink enough, toxins start accumulating in the blood, as there isn't enough fluid to drain them through the kidneys. You shold drink more than 10 glasses of water daily.

Too much protein
Over-consumption protein-rich foods such as red meat can deteriorate already damaged kidneys. A protein-rich diet is essentially healthy unless you suffer from kidney damage and kidney disease. Too much protein increases the metabolic load on our kidneys.

Comment: There is no evidence that protein intake negatively influences renal health in otherwise healthy, active individuals, however there is some evidence that already impaired renal function might worsen with increased protein: Is Eating Too Much Protein Going to Harm My Kidneys?

Hold urine
Holding urine for long time can damaged the kidneys. Holding a full of urine bladder for a long long time, can cause complications in the urinary tract and increased pressure of urine in the kidneys.

Magnesium deficiency
If you are magnesium deficient, calcium won't be properly absorbed and assimilated, which can result in the formation of kidney stones. To prevent that, consume green leafy vegetables, beans, seeds and nuts. The mighty avocado is a good source of magnesium as well.

Carbonated Drink
Drinking carbonated [sodas] are very harmful to the health of your kidneys and unfortunately it is consumed worldwide mostly by young people. In the long run, they will produce chronic kidney deficiency or stones and hence damaged kidney[s].

Vitamin B6 deficiency
According to the studies, vitamin B6 deficiency increases your risk of kidney stones. For optimal kidney function, you should get at least 1.3 milligrams of vitamin B6 daily. The richest sources of this vitamin include fish, chickpeas, beef liver, potatoes and starchy vegetables, and non-citrus fruits.

Taking too much sodium
Salt is important for the body, but you should limit your intake. Over consumption of salt increasing blood pressure and increasing strain on the kidneys. No more than 5.8 grams of salt should be eaten daily.

Comment: Salt has gotten an unfair rap from mainstream medicine. It's a good idea to switch from using regular table salt which is heavily processed, devoid of trace minerals, and commonly contains undesirable additives. Sea salts contain essential and nonessential trace elements.
  • Shaking Up The Salt Myth: Healthy Salt Recommendations

Consumption of too much caffeine
Drinking too much caffeine can damage the kidneys. Too much caffeine can elevate blood pressure and high blood pressure puts a strain on the kidneys which can damage them.

According to studies eating more than 2,200 calories a day could increase the risk of kidney stones by 42%. This may be because people who are obese tend to eat more salt and protein which leads to the formation of kidney stones.